Parvamussium undisonum

Dijkstra, 1995



       rv                     Holotype                           lv

Original name   Parvamussium squalidulum Dijkstra, 1995
Autoreference   Dijkstra, 1995: 37, figs 55-58.
Reference   Dijkstra, H.H., 1995. Bathyal Pectinoidea (Bivalvia: Propeamussiidae, Entoliidae, Pectinidae) from New Caledonia and adjacent areas. In: P. Bouchet (ed.), Résultats des Campagnes MUSORSTOM, volume 14. - Mémoires du Muséum National d'Histoire Naturelle 167: 9-73, figs 1-154.
Type data   Holotype (pr: H 14.2 mm, L 13.9 mm, D 3.1 mm) Museum National d'Histoire Naturelle, Paris (MNHN). Type locality: Loyalty Islands, 20*48'S, 167*05'E, 700 m, alive (MUSORSTOM 6 stn DW 489).

  Shell small up to ca. 14 mm high, fragile, semi-transparent white, weakly inflated, higher than wide, left valve slightly more convex than right valve, inequivalve, somewhat inequilateral, auricles nearly equal in size, relatively small, umbonal angle ca. 90 degrees.

  Left valve sculptured with undulating commarginal lamellae crossing irregularly irregularly spaced radial costae, enlarging towards ventral margin. Auricles with delicate commarginal lamellae. Right valve with regularly spaced, fine undulating commarginal lamellae. Byssal notch relatively deep, byssal fasciole narrow. Internal riblets 9-10 (4 rudimentary), extending to the submarginal region. Fasciolar pseudo-ctenolium present, with one active tooth. Marginal apron (below the interior riblets) of right valve often broken off.



Solomons, New Caledonia, Loyalty Islands (TL), New Hebrides, Tonga, Fiji, Vanuatu, Wallis & Futuna

Habitat   Living bathyally on soft bottom assemblages.